Who benefits from the Al Jazeera 'A-bomb"?

I blogged earlier today about the big "A-bomb" that al-Jazeera dropped on the Middle East and passed on to the Guardian, about the sorry state of Israeli-Palestinian peace talks. (Here's the link to the al Jazeera main webpage for the coverage, to make sure it gets its due.)

An Al Jazeera explainer page notes what's behind the papers:

There are 1,684 total documents, including
* 275 sets of meeting minutes;
* 690 internal e-mails;
* 153 reports and studies;
* 134 sets of talking points and prep notes for meetings;
* 64 draft agreements;
* 54 maps, charts and graphs;
* and 51 “non-papers.”

Among the bombshells, in numerous sublinks at the Guardian?

But, why? And why now?

The cui bono question is running through my head, mainly.

Yes, we know that WikiLeaks had the U.S. diplomatic cables, but the al-Jazeera leak is separate. So, who gave it what it got and why? And, how did that person come into the info, if he or she isn't an insider?

Would this benefit an Israeli ultrahawk like Avigdor Lieberman? By deliberately sabotaging future talks, which it will?

Or, somebody from Hamas? Though it would be tough for anybody from Hamas to have gotten such detailed information.

Or, either a rival to Abbas for leadership within the PA, or a principled PA negotiator who finally had had enough?

Meanwhile, Team Obama threatened to cut off funds to the Palestinian Authority if it replaced Mahmoud Abbas as leader.

This would be the same Abbas whose negotiating team, in private, officially accepted that Israel could define itself as a Jewish state.

This all further impinges on the "who benefits" issue.

And, was this leak, whoever did it, already planned before the WikiLeaks release of the U.S. cables or not?

Who doesn't benefit? Per one al Jazeera piece, everyday Palestinians, likely to see further Israeli intimidation and violence.